How about an egg timer ON the egg

DESPITE the best efforts of Delia Smith, millions of Britons will readily admit that they cannot boil an egg.

The experts at the British Egg Information Service have been inundated with queries â€” so much so that they have decided to eliminate the guesswork once and for all.

Their solution? A self-timing egg imbued with the powers of heat-sensitive invisible ink that turns black the minute that it is ready. All you need to do is decide whether you prefer your eggs soft, medium or hard-boiled, and buy accordingly.